January 16, 2021
Summary: It is wall to wall hazy sunshine out there this afternoon with some high, very thin cirrus clouds moving in from time to time. Temperatures are a few degrees cooler this afternoon, though still well above average. This is the first indication that upper level high pressure just to our west is beginning its trek further out over the ocean. A very fast moving wave of low pressure will move through Sunday night. the low will begin to form a new low pressure circulation just off the central coast early Monday morning then will race southward over southern California Monday, forming a cut off low off of northern Baja by Tuesday morning. at the surface, a very strong surface high will center over Montana and Idaho while that high, which by this time will have drifted off shore, builds a sharp ridge northeastward into western Canada. This will generate a strong northeast flow aloft over central California. With pressure much higher over the Great Basin than to our south, a powerful off shore flow will develop. It takes a number of ingredients to generate a Mono wind event, but on paper it’s really close. For Monday afternoon through Tuesday morning, it’s possible very strong winds out of the east could occur, especially down east to west facing canyons from Kings Canyon north. In the meantime, strong Santa Ana winds will be plaguing the mountains and coastal regions of southern California. As the surface flow becomes almost east to west Monday night and Tuesday morning, it’s possible strong, gusty, east to southeast winds could make it down to the extreme south valley floor. The low will also begin to pick up moisture, spreading showers over northern Baja and northward into Arizona and southern California from the Coachella Valley south. There are concerns about overnight low temperatures next week which are discussed below in the frost discussion. The Baja storm will be spanked eastward by a very cold low from western Canada which will drop into California Friday and Saturday. the bulk of the counterclockwise circulation of this feature will be overland, meaning it’s moisture field will be limited. Even so, there will be a small chance of light showers later Friday and Saturday.
Forecast: Mostly clear skies tonight with areas of fog and low clouds developing, mainly up the center of the valley after midnight. Areas of fog and low clouds Sunday morning. clearing in most areas by noon. Partly cloudy Sunday afternoon. Variable cloudiness Sunday night and Monday with gusty north to northwest winds down the west side of the valley. Partly cloudy Monday night through Wednesday. there’s a chance of strong, gusty, Santa Ana winds in the extreme south valley Monday afternoon through Tuesday morning. otherwise generally partly cloudy Tuesday through Thursday night. increasing cloudiness Friday leading to a minimal chance of light showers Friday afternoon through Saturday.
Short Term:
Madera 36/67/39/64 | Reedley 36/68/39/65 | Dinuba 35/66/38/65 | |
Porterville 36/70/40/64 | Lindsay 34/69/39/65 | Delano 38/70/40/66 | |
Bakersfield 44/70/45/64 | Taft 52/69/54/61 | Arvin 39/72/42/65 | |
Lamont 38/71/41/65 | Pixley 38/68/40/65 | Tulare 35/65/38/64 | |
Woodlake 35/68/39/65 | Hanford 38/67/40/65 | Orosi 34/67/39/65 |
Winds: Winds will be light and variable with periods of near calm conditions through Sunday. Winds along the west side will begin to increase late Sunday night through Monday night out of the north to northwest at 15 to 30 MPH with stronger gusts. Winds elsewhere will be mainly out of the northwest at 8 to 15 MPH with stronger gusts. It’s possible strong, gusty winds out of the east or southeast could develop Monday afternoon through Tuesday morning. if these winds do develop, gusts to 50 to 60 MPH could develop at places such as the bottom of the Grapevine and other wind prone locations. The chance of this occurring I would put at about 30% to 40% or so.
Rain: There is a chance of light snow showers over the southern Sierra Nevada late Sunday night through Tuesday with dry conditions continuing on the valley floor. Dry conditions will continue through Thursday night. I want to maintain a small chance of light showers in the forecast later Friday and Saturday as a potentially very cold low drops southward from western Canada and into California. This storm will be mainly tracking overland, meaning it will have a limited moisture field. If precipitation does occur, only light amounts can be expected.
Frost: All locations will be above 32 degrees through Monday morning. models continue to track a radical change in the pattern beginning tomorrow night. upper level high pressure which has been parked off the southern California coast the past few days will move further west out over the ocean and will build a southwest to northeast oriented ridge into western Canada. A fast moving wave of low pressure will drop southward through central California Monday morning, forming a closed low over California. It will develop a cutoff low off the northern Baja coast by Tuesday morning. the other player in this game is a very strong surface high which will center over Montana and Idaho by Monday night. all of these factors will lead to a very strong off shore flow, both at the surface and aloft. Although this air mass is not critically cold, it will be accompanied by tremendous wind energy above the valley floor and strong gusty winds along the west side of the valley late Sunday night through Monday night. A Mono wind event is even possible over the southern portion of the Sierra Nevada, leading to a new recipe for the character of the air mass on the valley floor with much lower dew points. We could see upper 20s to lower 30s by Tuesday morning and, if dew po ints fall far enough, some mid to upper 20s by Wednesday and Thursday mornings. However, it’s also possible that the cloud canopy from that low to our south could move far enough to the north to throw cloud cover over the valley, holding temperatures up.
If this sounds like a meteorological nightmare, it is.
Lows Tonight:
All locations will be above 32 tonight.
Next update: January 17/am